Chromospheres of late-type active and quiescent dwarfs. I. An atlas of high resolution Ca II H profiles

As a result of a major programme of spectral observations using the CAT 1.4 m telescope and Coude Echelle Spectrograph at ESO, La Silla, we have at our disposal 68 high resolution profiles of the 3968.5 A Ca H resonance line from 16 late type stars (dwarfs and subgiants, including the Sun) ranging from F9 to K5, selected to be representative of a wide span of chromospheric activity. In this paper we present the methods, and the results, of a set of reduction and analysis techniques applied to these spectra. We convert each wavelength scale to a frame at rest with respect to the photosphere of the star, and finally transform the flux scale into units of absolute flux. A major effort was applied to quantify the effects of the tilted baselines of the recorded spectra on these absolute flux calibrations. From the calibrated profiles we extract and tabulate measured chromospheric H emission fluxes, and the velocity shifts with respect to the photosphere of the emission cores and of the H3 self-reversals